<?php

    /**
     * PHPExcel_Worksheet_RowCellIterator
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_Worksheet
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */
    class PHPExcel_Worksheet_RowCellIterator extends PHPExcel_Worksheet_CellIterator implements Iterator {
        /**
         * Row index
         * @var int
         */
        protected $rowIndex;
        /**
         * Start position
         * @var int
         */
        protected $startColumn = 0;
        /**
         * End position
         * @var int
         */
        protected $endColumn = 0;

        /**
         * Create a new column iterator
         * @param    PHPExcel_Worksheet $subject     The worksheet to iterate over
         * @param   integer             $rowIndex    The row that we want to iterate
         * @param    string             $startColumn The column address at which to start iterating
         * @param    string             $endColumn   Optionally, the column address at which to stop iterating
         */
        public function __construct(PHPExcel_Worksheet $subject = null, $rowIndex = 1, $startColumn = 'A', $endColumn = null) {
            // Set subject and row index
            $this->subject  = $subject;
            $this->rowIndex = $rowIndex;
            $this->resetEnd($endColumn);
            $this->resetStart($startColumn);
        }

        /**
         * (Re)Set the end column
         * @param string $endColumn The column address at which to stop iterating
         * @return PHPExcel_Worksheet_RowCellIterator
         * @throws PHPExcel_Exception
         */
        public function resetEnd($endColumn = null) {
            $endColumn       = ($endColumn) ? $endColumn : $this->subject->getHighestColumn();
            $this->endColumn = PHPExcel_Cell::columnIndexFromString($endColumn) - 1;
            $this->adjustForExistingOnlyRange();
            return $this;
        }

        /**
         * Validate start/end values for "IterateOnlyExistingCells" mode, and adjust if necessary
         * @throws PHPExcel_Exception
         */
        protected function adjustForExistingOnlyRange() {
            if ($this->onlyExistingCells) {
                while ((!$this->subject->cellExistsByColumnAndRow($this->startColumn, $this->rowIndex)) && ($this->startColumn <= $this->endColumn)) {
                    ++$this->startColumn;
                }
                if ($this->startColumn > $this->endColumn) {
                    throw new PHPExcel_Exception('No cells exist within the specified range');
                }
                while ((!$this->subject->cellExistsByColumnAndRow($this->endColumn, $this->rowIndex)) && ($this->endColumn >= $this->startColumn)) {
                    --$this->endColumn;
                }
                if ($this->endColumn < $this->startColumn) {
                    throw new PHPExcel_Exception('No cells exist within the specified range');
                }
            }
        }

        /**
         * (Re)Set the start column and the current column pointer
         * @param integer $startColumn The column address at which to start iterating
         * @return PHPExcel_Worksheet_RowCellIterator
         * @throws PHPExcel_Exception
         */
        public function resetStart($startColumn = 'A') {
            $startColumnIndex  = PHPExcel_Cell::columnIndexFromString($startColumn) - 1;
            $this->startColumn = $startColumnIndex;
            $this->adjustForExistingOnlyRange();
            $this->seek(PHPExcel_Cell::stringFromColumnIndex($this->startColumn));
            return $this;
        }

        /**
         * Set the column pointer to the selected column
         * @param string $column The column address to set the current pointer at
         * @return PHPExcel_Worksheet_RowCellIterator
         * @throws PHPExcel_Exception
         */
        public function seek($column = 'A') {
            $column = PHPExcel_Cell::columnIndexFromString($column) - 1;
            if (($column < $this->startColumn) || ($column > $this->endColumn)) {
                throw new PHPExcel_Exception("Column $column is out of range ({$this->startColumn} - {$this->endColumn})");
            } elseif ($this->onlyExistingCells && !($this->subject->cellExistsByColumnAndRow($column, $this->rowIndex))) {
                throw new PHPExcel_Exception('In "IterateOnlyExistingCells" mode and Cell does not exist');
            }
            $this->position = $column;
            return $this;
        }

        /**
         * Destructor
         */
        public function __destruct() {
            unset($this->subject);
        }

        /**
         * Rewind the iterator to the starting column
         */
        public function rewind() {
            $this->position = $this->startColumn;
        }

        /**
         * Return the current cell in this worksheet row
         * @return PHPExcel_Cell
         */
        public function current() {
            return $this->subject->getCellByColumnAndRow($this->position, $this->rowIndex);
        }

        /**
         * Return the current iterator key
         * @return string
         */
        public function key() {
            return PHPExcel_Cell::stringFromColumnIndex($this->position);
        }

        /**
         * Set the iterator to its next value
         */
        public function next() {
            do {
                ++$this->position;
            } while (($this->onlyExistingCells) && (!$this->subject->cellExistsByColumnAndRow($this->position, $this->rowIndex)) && ($this->position <= $this->endColumn));
        }

        /**
         * Set the iterator to its previous value
         * @throws PHPExcel_Exception
         */
        public function prev() {
            if ($this->position <= $this->startColumn) {
                throw new PHPExcel_Exception("Column is already at the beginning of range (" . PHPExcel_Cell::stringFromColumnIndex($this->endColumn) . " - " . PHPExcel_Cell::stringFromColumnIndex($this->endColumn) . ")"
                );
            }
            do {
                --$this->position;
            } while (($this->onlyExistingCells) && (!$this->subject->cellExistsByColumnAndRow($this->position, $this->rowIndex)) && ($this->position >= $this->startColumn));
        }

        /**
         * Indicate if more columns exist in the worksheet range of columns that we're iterating
         * @return boolean
         */
        public function valid() {
            return $this->position <= $this->endColumn;
        }
    }
